# IT:AD:D3.JS:HowTo:Transitions # * [[../|(UP)]] {{indexmenu>.#2|nsort tsort}} ## Process # Recap: * when you `selectAll` you are getting an Array of DOM elements (actually an array of arrays, but lets gloss over that for now) * when you apply `data()` to a *selection* the data is embedded in the dom element (yeah...I was a bit surprised the first time I learnt that). * it's the equivalent of calling `d3.select('div').datum(whatever)` on the dom element. So here's an example of: * binding some data to some elements * getting a single element * updating its datum * applying another transition. An alternative way of selecting a single element -- or any subset of an element is as follows: But in most cases I'll bet you'll be updating, or reimporting fresh data - in which case you'll want to update the whole set again: